Beecher received a BA degree in 1926 and an MA degree in physical chemistry in 1927, both from the University of Kansas. While it had been his goal to earn a Ph.D. in chemistry at the Sorbonne, Henry was "persuaded" to study medicine instead.[4] Entering the Harvard Medical School in 1928, Beecher received research fellowships in 1929, 1930 and 1931. Beecher graduated cum laude in 1932. Two of his articles published in the Journal of Applied Physiology in 1933 earned Warren Triennial Prizes. These two articles and a study in Beecher's last year of college caught the attention of Harvard Professor of Surgery, Edward Churchill, M.D., who became his professional mentor. Post-college, he trained for two years under Churchill at Massachusetts General Hospital. Henry traveled to Denmark in 1935 to work in the physiology laboratory of Nobel LaureateAugust Krogh.[4]

Returning to America in 1936, Beecher was hired as Anaesthetist-in-Chief at MGH and Instructor in Anaesthesia at Harvard Medical School by Dr. Churchill. Henry became an Associate Professor in 1939 and the Henry Isaiah Dorr Professor of Anaesthesia Research in 1941—the first endowed chair in anesthesiology in America.[4]

During World War II, Beecher served in the U.S. Army with Dr. Churchill in North Africa and Italy. His experiences during the war in clinical pharmacology would inspire him to investigate placebo-like phenomena.[4]

As professor of anesthesiology at Harvard Medical School, Beecher published a 1966 article that drew attention to 22 examples of unethical clinical research that had risked patients' lives.[6] Though heralded for the position of this article, he was severely criticized by the medical establishment for what was felt as an unfair generalization from a few select cases.[4] However, this article and the subsequent Congressional investigation laid the foundation for current guidelines on informed consent and human experimentation.

In July 2007 the public German TV-channel SWR claimed that Beecher was involved as scientific expert with CIA studies on human drug experiments in the 1950s and may have contributed with his work in the United States and in secret CIA-prisons in Western-Germany to the KUBARK Counterintelligence Interrogation document of 1963.[7][need quotation to verify]

According to these recent reports, and also according to US-historian Alfred W. McCoy, Dr. Beecher was scientifically responsible for human experiments with drugs (e.g. mescaline) conducted by the CIA in post-war Germany. They took place in a secret CIA-prison located in "Villa Schuster" (later renamed to "Haus Waldhof") in Kronberg near Frankfurt, which was related to the nearby US-interrogation center Camp King (West-Germany). According to a witness, during these experiments, several interrogated individuals died. This report states that since September 1951, Beecher was frequently in Camp King and prepared human experiments, deliberated with the interrogation-staff of the CIA (called "rough boys") and recommended the test of various drugs. Several times he allegedly met with former Nazi-physician Walter Schreiber (at Camp King respectively in Villa Schuster) for an "exchange of ideas". Later Beecher described Schreiber in a report as "intelligent and cooperative."

The documents presented in the TV-documentation state that the US Army had sent reports about Nazi-experiments in concentration camps like Dachau to Dr. Beecher for evaluation. The library of Harvard Medical School still possesses a report of the US-army about these Nazi-experiments that it inherited from Dr. Beecher, a report which he evaluated.[8]

According to the German documentarian Egmont R. Koch, in January 1953, a depressive patient at the New York State Psychiatric Institute and Hospital got — upon recommendation of Dr. Beecher — a mescaline-injection at 9:53, fell in a deep coma at 11:45 and died within half an hour.[7]

According to the neuroanesthesiologist George A. Mashour:

It may appear paradoxical that Beecher, who advocated the ethical treatment of human subjects, had also engaged in potentially unethical work on hallucinogens for the government. A more compelling hypothesis, however, is that Beecher advocated ethical treatment of human subjects largely because of such work.[9]

The general literature[citation needed] commonly misattributes the term "placebo effect" to Henry K. Beecher's 1955 paper The Powerful Placebo. While this paper did not introduce the idea of placebo reactions (the term had been first used by Graves in 1920[citation needed]), its importance was that it stressed—for the first time—the necessity of double-blind, placebo-controlled clinical trials. In his 1955 paper, Beecher only speaks of placebo effects on specific occasions when he is contrasting them with drug effects. His 1955 paper constantly and correctly speaks of "placebo reactors" and "placebo non-reactors"; furthermore, Beecher (1952), Beecher, Keats, Mosteller, and Lasagna (1953), Beecher (1959), consistently and correctly speak of "placebo reactors" and "placebo non-reactors"; they never speak of any "placebo effect"; and, finally, in his Research and the Individual: Human Studies (1970), Beecher simply speaks of "placebos".